For ALL Possible, whether REC or TEC certified Depending on your certification, we dive in the cavern area - yellow system - or feel Free your mine for this weekend! In 1878, the miners began excavating the first tunnel there. At times, up to 200 workers were employed in the extraction and processing of roofing slate and slabs. In the more than 100 years of operation of this mine, a truly unique and huge mining labyrinth was created with kilometers of tunnels and huge halls on five levels and an extension of around 20 kilometers. Inclined tunnels, known as "Bremsberge", connect the various levels and conveyor lines with each other. After the mine was closed in 1985, the power was switched off and with it the pumps that pumped the constantly penetrating water into the Ruhr. It then took more than seven years for the water level to reach its current level. Of the total of five levels, the lower two are completely flooded over a length of approx. 12 km: on the middle conveyor section, you can reach a maximum depth of 14 meters and on the lower conveyor section, depths of up to 30 meters can be reached. You dive through long corridors lined with artfully stacked mountain walls and pass through excavations that are so large that they look like cathedrals. Underwater, divers will find everything as it was once left by the miners. This mine is really huge compared to other mines and the diver can explore anew with every dive. One of the routes takes you through narrow, sometimes very high corridors, large halls and past some trolleys on their tracks. The compressed air-powered overhead loader and an old break room, where the miners' jackets still hang on the wall, are certainly an "attraction". We don't want to tell you too much here...